Many type of catheters have been developed for treating problems and diseases of the body including the vascular, urinary, respiratory, esophageal, gastrointestinal systems and the like, as such body systems include one or more body lumens by which treatment can be facilitated. Such catheters advantageously provide treatment within or beyond any body lumen by generally non-invasive techniques by permitting manipulation of distal features of such catheters at their proximal ends. These features include balloons, such as are usable for percutaneous transluminal angioplasty (PTA) and percutaneous transluminal coronary angioplasty (PTCA), as well as features for delivering medical devices, such as stents and the like. Sometimes, these therapeutic catheterization techniques involve the use of a guide wire that is first controllably inserted within the body followed by sliding a catheter comprising tubing, in the form of one or more lumens, along the guide wire to the appropriate treatment site. Other times, the catheter, whether comprising tubing components or not, is inserted and directed to a treatment site without a guide wire.
For example, a balloon catheter for intravascular treatment is typically delivered along a guide wire. A typical balloon catheter has an elongate shaft with an inner lumen and has a dilatation balloon attached proximate the distal end and a manifold attached proximate the proximal end. These catheters are designed for introduction into a body lumen over the guide wire, which guide wire is slidably received within the inner lumen of the catheter. In use, the balloon catheter is advanced over the guide wire such that the dilatation balloon is positioned adjacent a restriction in a diseased vessel. Then, fluid under pressure is supplied to the balloon through the catheter lumen, expanding the balloon and opening the occlusion in the vessel. Balloon catheter systems are described, for example, within U.S. Pat. Nos. 5,797,878, 5,931,812 and 5,948,345.
For stent delivery, systems have been developed utilizing catheters as part of the stent delivery system. In some applications, balloon catheters may be used to deliver stents where a stent can be delivered to a desired treatment site as a collapsed structure provided about a balloon. At the site, the balloon can be expanded to set the stent in place. One specific example of such a balloon expandable stent delivery system is described in U.S. Pat. No. 6,270,504. Other stents, such as self-expanding stents, may also be delivered by catheter systems. In such a system, a catheter may be used to deliver a self-expanding stent to a treatment site, wherein the stent may be constrained by an outer sheath. Once the stent is properly positioned by manipulating the catheter, the outer sheath can be pulled away, such as by pulling a wire connected to the outer sheath, thereby allowing the self-expanding stent to expand and set in place. Examples of self expanding stent delivery systems are described in U.S. Pat. Nos. 6,254,609, 6,254,611 and 6,258,099.
In order to be properly introduced, delivered and controlled, catheters of all types are designed to accommodate needs for effective insertion within a body lumen and control of the catheter distal end by manipulation of the catheter proximal end. However, given the relatively small size of such medical products and their components, and the significant length that such catheters are to be inserted within a body lumen, it is increasingly difficult to incorporate more functional features and greater controllability to catheter constructions.
Moreover, the assembly of such small components of same or different materials requires difficult bonding techniques that are limited in applicability, not only by their material compatibility limitations, but also by the need to reliably bond components in an effective and medically sanitary way. As such, techniques to provide adhesive and weld bonds between catheter sections or portions or other catheter features, whether of similar or different materials, have been developed. Importantly, however, because of the eventual use of catheters well within body lumens, all such bonds or connections are desirably consistent and complete to ensure reliable usage with minimal body intrusion. In addition, for features such as balloons that require fluid tight sealing for operability, such fluid tight bonding should be of sufficient strength to withstand the fluid pressures involved in balloon dilatation without sacrificing insertability or controllability of the catheter.